A touch screen position sensor can detect the presence and location of a touch, by a finger or an object, such as a stylus, within a display area of the position sensor overlaid on a display screen. In a touch sensitive display application, the position sensor enables a user to interact directly with what is displayed on the screen, rather than indirectly with a mouse or touchpad. Position sensors can be attached to or provided as part of computers, personal digital assistants, satellite navigation devices, mobile telephones, portable media players, portable game consoles, public information kiosks, point of sale systems, etc. Position sensors have also been used as control panels on various appliances.
There are a number of different types of position sensors/touch screens, such as resistive touch screens, surface acoustic wave touch screens, capacitive touch screens, etc. A capacitive touch screen may include an insulator coated with a transparent conductor in a particular pattern. When a finger or object touches or is provided in close proximity to the surface of the screen, there is a change in capacitance. This change in capacitance is sent to a controller for processing to determine the position of the touch on the screen.
In recent years, the drive and/or sense electrodes of the touch screen have been interpolated in order to increase the resolution of larger screens. For example, the density of the electrodes or electrode segments may increase, decrease, or vary in one or more directions over the surface of the substrate. This interpolation allows for detection of a finger or other object according to the number of electrodes or electrode segments that sense the finger or object. However, the drive and/or sense electrode patterns which can be used have been constrained because adjacent electrodes are electrically isolated from one another.